Not Applicable
The present invention relates to electrical systems for automobiles and the like and, in particular, to a protective heat shield for protecting temperature sensitive electronic components from engine heat.
Present day automobiles and other vehicles make use of sophisticated electronics for engine control and monitoring. Typically one or more microprocessor-based electronic control units collect engine data from sensors located in different points on the engine and about the engine compartment. The control unit executes a stored control program to produce control signals for actuators such as fuel injectors, throttle plate spark coils and the like.
The complex circuitry of the control units is temperature sensitive and thus may be mounted in a cooler portion of the engine compartment, typically against or within the firewall to provide the desired reliability of the electronics. A lengthy and complex wiring harness is necessary to communicate between the control unit and its associated sensors and actuators.
This wiring harness could be significantly shortened and simplified if the control modules could be moved to the engine. While in some cases it is possible to obtain high temperature components that may withstand engine temperatures, these parts can be unduly expensive, and high temperature versions of some components, such as electrolytic capacitors, are not readily available.
The present invention provides a fluid cooled heat shield that permits proximate mounting of heat sensitive control electronics on or near the engine. The shield may be relatively compact because it is not intended to cool the engine but only to block a limited path of heat flow to the sensitive electronic components. By placing temperature sensitive control components in the xe2x80x9cheat shadowxe2x80x9d of the shield near the engine, wiring harnesses are reduced in length and simplified.
Specifically, the invention provides a system for protecting temperature sensitive vehicle electronics from engine heat by using a heat shield positioned, at least in part, between the control electronics and a high temperature engine component, wherein the heat shield includes a chamber holding a coolant fluid and providing a path of fluid circulation within the chamber for the removal of heat therefrom.
It is thus one object of the invention to provide a compact thermal barrier permitting sensitive electronics to be positioned close to the engine.
The chamber may include an inlet and outlet port and the coolant fluid may be an engine fluid, for example, transmission fluid, radiator fluid, ambient air or engine intake air, pumped through the chamber between the inlet port and the outlet port.
Another object of one embodiment of the invention is to provide a heat shielding system that may make use of cooling systems normally associated with the automotive engine.
In an alternative embodiment, the chamber may be sealed and include a radiating end having at least one fin and the fluid may be selected from those having vaporization temperatures below the temperature of the high temperature engine components so as together, with the chamber, to form a heat pipe.
Thus it is another object of the invention to provide self-contained heat shielding.
The heat shield may include a heat sink communicating between the control electronics and the chamber for transferring heat from the control electronics to the cooling fluid.
Thus it is another object of the invention to make additional use of the heat shield as a sink for heat generated by the electronics itself.
The foregoing and other objects and advantages of the invention will appear from the following description. In this description, reference is made to the accompanying drawings, which form a part hereof, and in which there is shown by way of illustration, a preferred embodiment of the invention. Such embodiment and its particular objects and advantages do not define the scope of the invention, however, and reference must be made therefore to the claims for interpreting the scope of the invention.